Conventionally, a machine tool is known that includes a workpiece holding unit to hold a workpiece, a tool rest to hold a cutting tool that cuts the workpiece, a feeding unit to feed the cutting tool toward the workpiece in a predetermined feeding direction via relative movement between the workpiece holding unit and the tool rest, a vibration unit to cause relative reciprocal vibration between the workpiece holding unit and the tool rest so that the cutting tool is fed in the feeding direction while reciprocally vibrating in the feeding direction, and a rotating unit to cause relative rotation between the workpiece and the cutting tool. An example of such a machine tool is described in paragraphs 0073 and 0078 and FIG. 7 of U.S. Patent Publication 2014/0102268, published Apr. 17, 2014.
A control apparatus of this machine tool drives and controls the rotating unit, the feeding unit, and the vibration unit and makes the machine tool machine the workpiece via relative rotation between the workpiece and the cutting tool and via the feeding of the cutting tool toward the workpiece with the reciprocal vibration in the feeding direction.